1. Field of the Invention
The present invention relates to a socket connector, and more particularly to a socket connector having improved datum blocks for accurately positioning an IC package and capable of preventing deformation of the protrusions.
2. Description of Related Art
Connectors are used for a number of applications. In one such application that occurs commonly in a computer system, a socket connector is provided to be mounted on a mother board for receiving an IC (Integrated Circuit) package. The socket connector generally comprises at least a socket body and an array of contact terminals mounted within the socket body. An IC package is placed onto the socket body and then brought into contact with the contact terminals in the socket body. The contact terminals are also electrically connected onto conductive pads disposed on the mother board, respectively, such that the electrical connection between the IC package and the circuit in the mother board is achieved. One of the problems encountered by the industry is the shrinkage of the plastic material during molding. The part intended for datum tends to deform because of deformation resulted from shrinkage.
U.S. Pat. No. 6,908,316 issued to Ma on Jun. 21, 2005 discloses a socket connector performing such a function as described above. Referring to FIGS. 1-5 of Ma, the socket connector includes an insulative socket body and a load plate pivotally coupled to one end of the socket body. The socket body has a cavity for receiving and securing IC package. To ensure a fine and true positioning of the IC package, a plurality of protrusions are provided on the sidewalls to extend inwardly from inner surfaces of peripheral sidewalls of the cavity. The IC package is constrained by the protrusions when placed in the cavity, such that precise alignment between the IC package and the contact terminals in the socket body is ensured. A soldering process in a high temperature environment is necessary to mount the socket connector onto a mother board. However, the accuracy of the protrusions that integrally formed with the sidewalls is like to be influenced by the deformation of the sidewalls that caused due to the high-temperature environment, such that the precise positioning of the IC package could not be guaranteed.
U.S. Pat. No. 7,056,130 issued to McAlonis et al. on Jun. 6, 2006 discloses a socket connector that includes an insulative socket body for receiving an IC package. Referring to FIG. 2 and FIG. 3, the insulative socket body has sidewalls distributed at corners thereof, respectively. Each side wall is integrally formed with a protrusion 192 that used to position the IC package. An improvement in McAlonis is made that the sidewalls are noncontinuous with each other and are relatively short in length. Therefore, the influence to the accuracy of the protrusion that caused by the deformation of the sidewalls is relatively small. However, the defect still exists in such a design.